With the rapid development of electronic technology, conventional electronic devices often can utilize a variety of antennas to receive different signals, for example, Bluetooth antenna, Near Field Communication (referred to as NFC for short) antenna, wireless charging antenna, etc.
Among them, the NFC antenna and the wireless charging antenna belong to application of electromagnetic induction, the Bluetooth antenna belongs to application of electromagnetic radiation, wherein an antenna of an electromagnetic induction type does not need a reference ground portion, whereas an antenna of an electromagnetic radiation type needs a reference ground portion.
In order to reduce a volume of the antenna of the electromagnetic radiation type, conventionally, the reference ground portion of the antenna of the electromagnetic radiation type is printed on a Printed Circuit Board (referred to as PCB for short) substrate, with a ceramic Bluetooth antenna shown in FIG. 1 as an example, a reference ground portion 12 is printed on a PCB substrate 11, a ceramic portion 13 is connected to the reference ground portion 12, wherein the ceramic portion 13 and the reference ground portion 12 constitute the entire ceramic Bluetooth antenna.
It's worth being noted that, in order to prevent copper coated on the PCB substrate from causing interference to the antenna of the electromagnetic radiation type, the PCB substrate requires a clearance area in the reference ground portion, thereby a dimension of the PCB substrate is increased.